This invention relates to the processing of shellfish, and more particularly relates to a method and apparatus for mechanically separating the viscera from the meat of shucked scallops.
Scallops, along with oysters, clams and mussels, are members of a group of marine shellfish called bivalve mollusks. Scallops have three major components: two hard outer shell sections or valves; viscera known as "rim"; and a single large adductor muscle (also known as the "meat" or "eye"). Also contained in the viscera are the eggs or ovaries, generally referred to as the "roe."
The commercial preparation of scallops for U.S. consumption involves shucking, followed by eviscerating. Shucking is the separation of the adductor muscle from the shell, and eviscerating is the separation in the shucked scallop of the viscera from the adductor muscle. Scallop eviscerating is distinguishable from shrimp peeling in that the former involves the separation of soft cylindrical muscle from soft, stringy viscera, while the latter involves the separation of soft edible meat from hard, plate-like shell segments.
In the commercial processing of scallops shucking and eviscerating are generally performed in two distinct operations, one continuously following the other. The method and apparatus of the present invention relate to the eviscerating procedure, and are not directly concerned with the means employed to shuck the scallops, the same being able to be accomplished by any of various well-known mechanical or hand shucking techniques.
Conventional methods and apparatus for mechanically eviscerating scallops are set forth in Willis U.S. Pat. Nos. 3,562,855, and Wenstrom et al. U.S. Pat. Nos. 3,665,554 and 4,532,677. The generally utilized method involves removing the viscera from the muscle employing a plurality of pairs of counter-rotating rollers, arranged to form an inclined path descending from the input end of the eviscerator table. Each of the rollers has its axis aligned transversely of the path and is positioned so that the surface of each intermediately positioned roller forms a nip with the adjacent roller on its input side and a nip with the adjacent roller on its output side. Drive means are provided for oscillating the rollers so that the upper exposed portion of adjacent rollers are alternately rotated toward each other to pull viscera from the scallop muscles and through the nip of the rollers, and alternately rotated away from each other to advance the scallops. The scallops move in the direction of the incline, substantially perpendicular to the axes of the rollers, being alternately pinched by the rollers and moved over the rollers from one roller to the next. A water spray is applied from above to the rollers to lubricate the rollers so that the scallop muscles rotate about their cylindrical axes.
There is an emphasis in conventional mechanical scallop eviscerating technology on moving the shucked scallops transversely over the roller pairs, down the direction of the incline. There has been an avoidance of eviscerating systems in which the scallops move longitudinally along rollers or roller channels, such as are known for mechanical shrimp peeling as illustrated by the equipment shown in the LaPeyre et al U.S. Pat. No. 2,778,055 of The Laitram Corporation, New Orleans, La., and other patents of the same assignee. Reported attempts by those involved in the development of systems, such as those shown in the Willis and Wenstrom et al patents, to adopt shrimp peeling techniques and machinery to scallop eviscerating have been unsuccessful and were abandoned, and both applicants and examiners involved with patenting of scallop eviscerating methods and apparatus have established positions that the same are involved in non-analogous art vis-a-vis shrimp peeling methods and apparatus.